Apparatus for treating wood



Sept. 20, 1938. E. L. FIICKETT E r AL 2,130,457

APPARATUS FOR TREATING WOOD Filed om. e, 1936 4 Sheet s-Sheet 1 V INVENTORS 7f 64 4 4221 @20 2777017. BY 9 1785%. FEE/fed, Cfidf/QSHWCW ATTORNEY 932 Se t. 20, 1938. E. L. FICKETT ET AL APPARATUS FOR TREATING WOOD Filed Oct. 6, 1956 4 Sheets-Sheet 2 INVENTORS W1: 0

Sept. 20, 1938. E. L. FICKETT ET AL 2,130,457

APPARATUS FOR TREATING WOOD 4 Sheets-Sheet 3 Filed Oct. 6, 1936 "'K ATTORNEY Wi Sept. 20, 1938. E. L. FICKETT ET AL APPARATUS FOR TREATING WOOD 4 Sheets-Sheet 4 Filed Oct. 6, 1936 Patented Sept. 20, 1938 UNITED STATES PATENT OFFICE APPARATUS FOR TREATING WOOD Ernest L. Fickett, William 0. Forman, and Charles H. McKay, Fitchburg, Mass, assignors to Fitchburg Engineering Corporation, Fitchburg, Mass, a corporation oi Massachusetts Application October 6, 1936, Serial No. 104,250

8 Claims. (Cl. 144-476) This invention relates to an apparatus for pro- Fig. 11 is an end view thereof; and ducing wood sawdust, shavings, excelsior, etc. Fig. 12 is an edge view of the same knife. in commercial form and the commercial utiliza- By this apparatus slabs, edgings or other mill tion of an otherwise waste product thereby. by-products are introduced into a chute and cut The principal objects of the invention are up in that chute by rotating blades so that the to provide for the cutting of wood, preferably fine wood products, which may be in the form waste pieces, into whatever shape and form is of long or short shavings, excelsior, etc. will be desired; to provide a machine which can be made produced. or adjusted in different forms so that the cut- The form of wood product is controlled by the ting will be done at different angles to the grain, shape of the cutting edge of the knives and lo thereby producing different products, such as angular position of the chute relative to the sawdust, long shavings, short shavings, excelsior, knives. In that form shown in Figs. 1 to 4 inetc.; to provide means whereby slabs, edgings, elusive, the axis of rotation of the cutter is horior other mill products can be converted into any zontal. The machine is supported by a base It form of wood in small pieces; to provide an imon which are mounted two bearings H and l2 15 proved form of hopper adjustable for feeding the carrying the main shaft I3 which may be coupled wood to the cutters at the desired angle; to directly with the main shaft of amotor it. The provide means for preventing a small piece of bearings H and I! are carried in casings mounted wood caught in the bottom of the hopper from on the base. escaping without going through the knives; to The main shaft i3 carries a cutter head i5 20 provide a chute with automatic means for feedwhich revolves in a stationary casing I6. On the ing a plurality of slabs, limbs, or the like, longibase is a block H on which through screws 98 a tudinally by a reciprocating motion, and to proslide i9 is adjustable. A chute, which comprises vide a piston head of such shape as to properly a back 2! and sides 20 mounted on the slide i9,

push the wood against the knives. has an open front facing the flat end of the 25 Other objects and advantages of the invention cutter disc l5. The top and sides of the chute will appear hereinafter. are cast integral but the back 2! of the chute Reference is to be had to the accompanying is hinged by means of a series of slots 22 in the drawings, in which sides of the chute and two pins on the back 2!.

Fig. 1 is a longitudinal central sectional view The back of the chute is free to slide to and. away 30 of a machine constructed according to this infrom the cutter disc l5 along the block ii. The vention; loosely hung back, which fits closely between the Fig. 2- is a similar sectional view, on enlarged sides of the chute, is held up in position by springs scale, showing the cutting operation to reduce 23 threaded on rods 24. By means of check a piece of wood into shavings; nuts 25 the rods provide for the adjustment of 35 Fig. 3 is a face view of a circular cutter plate the minimum position of the back. These nuts constituting a part of this machine; also prevent the back from contacting with the Fig. 4 is a radial sectional view of the cutter knives. plate; The cutter disc i5 is shown as provided with F 5 1s a sectional e of an e d bearing six generally radial openings 26 with inclined 40 showing the hydraulic pump used in this invensides and six knives 21 and 31 also running in a tion; general radial direction and bolted to the sides.

Fig. 6 is a side view of a preferred form of feed For the purpose of reducing the friction loss chute in which the wood is presented to the and the abrasions on the front surface of the knives at a 60 angle for the production of short cutter head a hardened steel insert 28 is located 45 shavings; in the front of each opening. The hardened steel Fig. 7 is a side view showing a feed chute that insert has a tapered surface at 29 so that the can be applied to Fig. 6; end opposite the cutting edge is a small dis- Fig. 8 is a face view of a knife adapted to be tance above the plate surface. The cutting used on this machine; knives 21 and 3| are arranged at quite an angle 50 Fig. 9 is a sectional view of the same on the to the flat surface of the disc and the way in line 9-9 of Fig.8; which a shaving is cut off from a piece 30 of Fig. 10 is a view similar to Fig. 8 showing anwood is illustrated in Fig. 2. other form of knife adapted to be used on this A construction is shown in which six knives are machine; equally spaced around the disc. Three of these 55 are the plain cutting knives 21 and the other three knives 3| have their cutting edge interrupted by grooves to form a series of chisel points 32. With this construction and arrangement and with the knives set with theircutting edges set at a short distance beyond the wear strips 23 the product will be sawdust when used in connection with Fig. 6. when used with Fig. 1 with all'the edges of all the blades straight, the product is shavings. With other arrangements other products can be made, as long shavings, excelsior, etc.

According to an application filed in the name of William O. Forman, October 25, 1937, Serial No. 170,823, but not apart hereof, the bark is broken up into dust while the wood. shavings processed material to any desired point by means of standard sheet'metal pipingf It has been found by experiment that-if the lower end of the back II of the feed chute is cut off parallel to the face of the disc, as'shown at 33, the wood will be assisted in being drawn toward the cutter. With the knives set at a suflicient distance beyond the strips .on the face of the disc, any slab, limb, edging, or section of tree lumber that is dropped into the chute will be converted into sawdust or shavings and discharged by the centrifugal blower.

So far only one form of the apparatus has been described, the one in which the axis 'of the shaft is horizontal with an acute angle between it and the chute and alternating continuous cutting edge and toothed cutting edged knives are used.

Obviously, all the knives can be of either type. The angle between the axis of the cutter shaft and the direction of the feed of the wood changes the product materially.

' It has been found by experiment that, if a horizontal feed chute is used and material fed to the disc with its grain running at right angles to the axis of the shaft and blades set so that they will cut the material, the wood is cut into wide, fairly straight shavings.

A preferred form of feed chute is shown in Fig. 6. This is arranged in such a manner that the wood is presented to the knives at an angle of approximately 60. Although not necessarily so this particular chute is provided with cutters having alternately serrated and straight edges to produce sawdust but short shavings would be produced if all the cutters were plain. The chute is provided with a movable end 33 or piston convex on the end operated by a feed cylinder 38 connected with the end through a piston rod 31. Attached to the end of a bearing opposite the drive pulley is a commercial gear pump 38 which is driven from the end of the main shaft, not shown in Fig. 6 but like the shaft l3. This pump is arranged to r constantly at all times when the machine is i operation and pumps the operating fluid, as oil, from the reservoir 33, and delivers it to a four-way manually operated valve 39 which is attached to the side of the chute. A predetermined pressure is maintained on the sys-' tem by means of a conventional spring-loaded relief valve 40 discharging back into the reservoir 33. arranged that when it is thrown into the proper position to feed the sticks or slabs toward the The manually operated valve '38 is sorotating knives, it is latched by a weighted lever 42 and remains-latched until the movable end or piston has gone practically its extreme travel. At that time a projection 43 on the piston "engages the latch and unlatches it. This latch is spring-operated into such a position that the movable piston 35 returns to the loading position.

In connection with the form of feed shown in Fig. 6, a preferred arrangement can be used for keeping the wood up against the knives. This is shown in Fig. '7 and it involves the sides and front 45 of a chute open at the bottom along an inclined surface 43 and having a pair of integral bars 41 which support the rod 24 and the spring 23 and nuts shown in Fig. 2. This rod is pivotally connected with the back 43 of the chute.

This back, which controls the position of the wood as it approaches the cutter, is cut oil at 33 to form a surface parallel with the face of the cutter disc as previously described. In this case also the back 43 can be supported by pins 43 entering into either oneof a set of inclined slots 50 in the sides 45 of the chute.

-Having thus described our invention and the advantages thereof, we do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what we claim is:

1. An apparatus for reducing wood to small particles which comprises a rotary cutter having a flat face perpendicular to its axis and a chute arranged to feed rough wood to the cutter with its grain at an acute angle of less than 45 to the plane of the face of the cutter, the cutter comprising knives set at a material angle to the face of the cutter to make long shavings.

' 2. An apparatus for reducing wood to small particles which comprises a rotary cutter having a flat face perpendicular to its axis, a chute arranged to feed rough wood to the cutter with its grain at an angle to the plane of the face of the cutter, the cutter comprising knives projecting from the face of the cutter, and means for varying the angle to minute degrees at which the wood engages the cutter to determine the character of the product.

3. An apparatus for reducing wood to small particles which comprises a rotary cutter having a flat face perpendicular to its axis and a chute arranged to feed rough wood to the cutter with its grain at a small angle to the plane of the face of the cutter, the chute having a spring pressed back plate movable to different angles, and ad- :Iustable means for determining the clearance between the back plate and cutters.

4. An apparatus for reducing wood to small particles which comprises a rotary cutter disc having a flat face perpendicular to its axis and a chute arranged to. feed rough wood to the cutter with its grainat an angle to the plane of the face of the cutter, the chute having a back plate,

the end of which nearest the cutter is flattened of! to be parallel to the face of the cutting disc.

5. In an apparatus for the purpose described,

the combination of a hopper in inclined position,

a piston in the hopper for feeding wood having a convex-toothed operating end for engaging the wood, hydraulic means forfeeding the plunger, a horizontal rotary shaft, a disc on the shaft arranged at right angles thereto, and knives on the to the cutter with its grain at an angle to the plane of the face of the cutter, a piston in the chute having a convex coarsely toothed working surface, automatic hydraulic means for moving the piston on its operative stroke, a valve for keeping the piston in communication with a source of power, a latch for holding the valve open, and means for automatically releasing the latch to permit the piston to move back.

'7. An apparatus for reducing wood to small particles whichcomprises a rotary cutter having a fiat face perpendicular to its axis, a chute arranged to feed rough wood to the cutter with its grain at an angle to the plane of the face of the cutter, the chute having a swing adjustable back plate, means for limiting the movement of the back plate toward the cutter to a position far enough from the cutter to receive the wood, and

yielding means for constantly pushing the back plate toward the cutter.

8. An apparatus for reducing wood to small particles which comprises a rotary cutter having a flat face perpendicular to its axis, a stationary chute arranged to feed rough wood to the cutter with its grain at an angle to the plane of the face of the cutter, the chute having a series of pairs,

ERNES L, F'ICKETT- 1 fa 0. RLES H. McKAY. 

